This invention relates to a device and process for converting random rocking motion into electrical energy. More particularly, the apparatus and process of this invention can be used to convert oceanic wave energy into electricity either on moored buoys or in small vessels.
Some systems for the conversion of ocean wave energy into electrical power have already been described. U.S. Pat. No. 4,178,517, for example, describes an apparatus which contains no moving parts. The apparatus of that invention comprises a floating cylinder with one open end submerged below sea level by a taut mooring. The cylinder is divided into an upper and lower chamber by a suitably supported protonic conductor mounted across the width of the interior. The protonic conductor is in contact with suitable electrodes which are connected to the electrical load. The inside of the cylinder is initially evacuated and then filled with hydrogen to some pressure. To prevent hydrogen loss, a flexible diaphragm, bellows or piston must separate this open end from the water. To operate as designed, the buoy must be held at a fixed distance from the floor of the sea by means of taut mooring. When the movement of the ocean causes the water level to rise, the pressure in the lower chamber increases and the hydrogen dissociates at the electrode. Protons migrate through the protonic conductor and electrons travel in the external circuit. In the upper chamber, recombination of protons and electrons occurs. The process is reversed when the water level falls. Similar constructions are described by R. E. Salomon, et al in Ocean Engineering, Vol. 6, pp. 317-327, 1979.
Other efforts to harness the motion of waves to produce electricity have been more conventional, utilizing conventional turbines or electrical generators mechanically driven by the motion of ocean waves. One such device is described in an article by M. E. McCormick in "A modified linear analysis of a wave energy conversion buoy", Ocean Engineering, Vol. 3, pp. 133-144. Such conventional power generation systems are subject to corrosion by the marine environment and mechanical parts require frequent maintenance.
The apparatus of the present invention comprises a floating buoy containing a U-tube which is allowed to rock back and forth by the ocean wave activity. Taut mooring is not required in this present invention and also, no flexible diaphragm, bellows or piston are required. Both of these factors render deployment of the present invention less costly and easier than the apparatus disclosed in U.S. Pat. No. 4,178,517.